 ///
 /// @file    namespace1.cc
 /// @author  lemon(haohb13@gmail.com)
 /// @date    2016-02-24 17:56:34
 ///
 
#include <iostream>

using std::cout;// using 声明机制
using std::endl;

namespace A
{

int num = 1;

void displayA()
{
	cout << "This is A" << endl;
}
}


namespace B
{
using A::displayA;

int num = 10;

void displayB()
{
	displayA();
	cout << "This is B" << endl;
}
}



int main(void)
{

	A::num = 110;

	A::displayA();
	using B::displayB;
	displayB();
}
